This application is based on Patent Application No. 2001-346331 filed Nov. 12, 2001 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a latch locking mechanism of a KGD carrier, and more specifically, to a latch locking mechanism of a KGD carrier which can be easily opened and closed.
2. Description of the Related Art
If a chip (die) which has met a specification but has not been packaged, i.e. a KGD (Known Good Die) is to be subjected to a burn-in test, the KGD is once mounted in a special carrier, and the carrier with the KGD mounted is further mounted in an IC socket. Subsequently, the IC socket is incorporated into a test board, to carry out a burn-in test.
The structure of the conventional carrier with the KGD mounted will be simply described with reference to FIG. 4. This figure is a sectional view of a carrier with an IC chip mounted.
The KGD carrier 10 comprises a carrier retaining member 20 and a carrier base assembly 30.
The carrier retaining member 20 has a cover 21, a chip retaining member 22, a coil spring 23, and a steel ball 24 to elastically hold an IC chip 40 placed on the carrier base assembly 30.
The carrier base assembly 30 has a carrier main body 31 including a latch 36, a substrate (contact sheet) 32 as a printed-circuit board, an elastomer frame 33, an elastomer 34 as a cushion, and a carrier base 35. The latch 36 has a locking portion 36a locked on the carrier retaining member 20 and a latch base 36b rotationally movably mounted on the carrier main body 31 and urged and biased toward the interior of the carrier base assembly 30 by a helical torsion coil spring 37.
The IC chip 40 is mounted in the carrier 10 in the following manner. First, with the carrier retaining member 20 removed, the IC chip 40 is placed on the substrate 32. Subsequently, the carrier retaining member 20 is used to uniformly and elastically push the IC chip 40 into tight contact with the substrate 32, thereby electrically connecting the IC chip 40 and the substrate 32 together. Furthermore, the latch 36 is engaged with the cover 21 of the carrier retaining member 20 to complete mounting the IC chip 40 as shown in the figure.
As shown in FIG. 4, at least two opposite latches 36 are required to engage the carrier retaining member 20 with the carrier base assembly 30 and also to uniformly tightly contact the IC chip 40 with the substrate 32. However, in the conventional carrier 10, the at least two opposite latches 36 are provided with the carrier main body 31. With this arrangement, when the carrier retaining member 20 is removed from the carrier base assembly 30, the two opposite latches 36 must be simultaneously rotationally moved outward in the opposite directions relating to the carrier retaining member 20. That is, the two opposite latches 36 must be simultaneously opened and disengaged (unlocked) from the carrier retaining member 20. Then, while maintaining this disengaged state, the carrier retaining member 20 must be removed from the carrier base assembly 30. Conversely, when the carrier retaining member 20 is installed on the carrier base assembly 30, this installation must be carrier out while keeping the two opposite latches 36 open.
A complicated structure is required to automatically install and remove the carrier retaining member 20 on and from the carrier base assembly 30 while keeping the at least two opposite latches 36 simultaneously open. If this is manually carried out, the operation is difficult. Furthermore, if for example, two sets of two opposite latches 36 are provided so as to cross at right angles, the complicity and difficulty enhance.
In view of these problems, it is an object of the present invention to provide a latch locking mechanism of a KGD carrier which has a simple structure and which facilitates the simultaneous opening and closing of latches and the installation and removal of a carrier retaining member.
To attain this object, a latch locking mechanism of a KGD carrier according to the present invention comprises a carrier retaining member having a cover and a chip retaining member, a carrier base assembly having a carrier main body, a substrate, and a carrier base, at least two opposite latches rotationally movably provided on a cover of the carrier retaining member and each including an operation portion and a locking portion which generally form an L shape, and engaging portions provided on the carrier main body of the carrier base assembly to engage with the corresponding locking portions of the latches. The latch locking mechanism is characterized in that when the locking portions of the two opposite latches are closed, the locking portions engage with the corresponding engaging portions provided on the carrier main body to lock the carrier retaining member and the carrier base assembly.
Further, each tip of the operation portions of the two opposite latches are preferably arranged close to each other with a small space.
Furthermore, two sets of the two opposite latches may be arranged so as to cross at right angles.
Moreover, at least two sets of the two opposite latches may be arranged so that the sets are parallel with each other and the operating portions of the sets are connected together.
Further, in the latch locking mechanism of a KGD carrier according to the present invention, the cover may have a groove portion which is formed of inclined surfaces having an inclination xcex1 from a horizontal surface and a concave portion so as to allow the operation portions of the two opposite latches to be rotationally moved.
Furthermore, the angle xcex1 and an angle xcex2 at which the locking portion of the latch can be cleared from the engaging portion of the carrier preferably has a relationship xcex1xe2x88x92xcex2=xe2x88x921 to +3xc2x0, more preferably a relationship xcex1xe2x88x92xcex2=0 to +3xc2x0.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.